/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkTransform.h

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/

// .NAME vtkTransform - describes linear transformations via a 4x4 matrix
// .SECTION Description
// A vtkTransform can be used to describe the full range of linear (also
// known as affine) coordinate transformations in three dimensions,
// which are internally represented as a 4x4 homogeneous transformation
// matrix.  When you create a new vtkTransform, it is always initialized
// to the identity transformation.
// <P>The SetInput() method allows you to set another transform,
// instead of the identity transform, to be the base transformation.
// There is a pipeline mechanism to ensure that when the input is
// modified, the current transformation will be updated accordingly.
// This pipeline mechanism is also supported by the Concatenate() method.
// <P>Most of the methods for manipulating this transformation,
// e.g. Translate, Rotate, and Concatenate, can operate in either
// PreMultiply (the default) or PostMultiply mode.  In PreMultiply
// mode, the translation, concatenation, etc. will occur before any
// transformations which are represented by the current matrix.  In
// PostMultiply mode, the additional transformation will occur after 
// any transformations represented by the current matrix.
// <P>This class performs all of its operations in a right handed
// coordinate system with right handed rotations. Some other graphics
// libraries use left handed coordinate systems and rotations.  
// .SECTION See Also
// vtkPerspectiveTransform vtkGeneralTransform vtkMatrix4x4 
// vtkTransformCollection vtkTransformFilter vtkTransformPolyDataFilter
// vtkImageReslice

#ifndef __vtkTransform_h
#define __vtkTransform_h

#include "vtkLinearTransform.h"

#include "vtkMatrix4x4.h" // Needed for inline methods

class VTK_COMMON_EXPORT vtkTransform : public vtkLinearTransform
{
 public:
  static vtkTransform *New();
  vtkTypeMacro(vtkTransform,vtkLinearTransform);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Set the transformation to the identity transformation.  If 
  // the transform has an Input, then the transformation will be
  // reset so that it is the same as the Input.
  void Identity();

  // Description:
  // Invert the transformation.  This will also set a flag so that
  // the transformation will use the inverse of its Input, if an Input
  // has been set.
  void Inverse();

  // Description:
  // Create a translation matrix and concatenate it with the current
  // transformation according to PreMultiply or PostMultiply semantics.
  void Translate(double x, double y, double z) {
    this->Concatenation->Translate(x,y,z); };
  void Translate(const double x[3]) { this->Translate(x[0], x[1], x[2]); };
  void Translate(const float x[3]) { this->Translate(x[0], x[1], x[2]); };

  // Description:
  // Create a rotation matrix and concatenate it with the current
  // transformation according to PreMultiply or PostMultiply semantics.
  // The angle is in degrees, and (x,y,z) specifies the axis that the
  // rotation will be performed around. 
  void RotateWXYZ(double angle, double x, double y, double z) {
    this->Concatenation->Rotate(angle,x,y,z); };
  void RotateWXYZ(double angle, const double axis[3]) {
    this->RotateWXYZ(angle, axis[0], axis[1], axis[2]); };
  void RotateWXYZ(double angle, const float axis[3]) {
    this->RotateWXYZ(angle, axis[0], axis[1], axis[2]); };

  // Description:
  // Create a rotation matrix about the X, Y, or Z axis and concatenate
  // it with the current transformation according to PreMultiply or
  // PostMultiply semantics.  The angle is expressed in degrees.
  void RotateX(double angle) { this->RotateWXYZ(angle, 1, 0, 0); };
  void RotateY(double angle) { this->RotateWXYZ(angle, 0, 1, 0); };
  void RotateZ(double angle) { this->RotateWXYZ(angle, 0, 0, 1); };

  // Description:
  // Create a scale matrix (i.e. set the diagonal elements to x, y, z)
  // and concatenate it with the current transformation according to
  // PreMultiply or PostMultiply semantics.
  void Scale(double x, double y, double z) {
    this->Concatenation->Scale(x,y,z); };
  void Scale(const double s[3]) { this->Scale(s[0], s[1], s[2]); };
  void Scale(const float s[3]) { this->Scale(s[0], s[1], s[2]); };

  // Description:
  // Set the current matrix directly.  This actually calls Identity(),
  // followed by Concatenate(matrix).
  void SetMatrix(vtkMatrix4x4 *matrix) { 
    this->SetMatrix(*matrix->Element); };
  void SetMatrix(const double elements[16]) { 
    this->Identity(); this->Concatenate(elements); };

  // Description:
  // Concatenates the matrix with the current transformation according
  // to PreMultiply or PostMultiply semantics.
  void Concatenate(vtkMatrix4x4 *matrix) { 
    this->Concatenate(*matrix->Element); };
  void Concatenate(const double elements[16]) {
    this->Concatenation->Concatenate(elements); };

  // Description:
  // Concatenate the specified transform with the current transformation
  // according to PreMultiply or PostMultiply semantics.
  // The concatenation is pipelined, meaning that if any of the
  // transformations are changed, even after Concatenate() is called,
  // those changes will be reflected when you call TransformPoint().
  void Concatenate(vtkLinearTransform *transform);

  // Description:
  // Sets the internal state of the transform to PreMultiply. All subsequent
  // operations will occur before those already represented in the
  // current transformation.  In homogeneous matrix notation, M = M*A where
  // M is the current transformation matrix and A is the applied matrix.
  // The default is PreMultiply.
  void PreMultiply() { 
    if (this->Concatenation->GetPreMultiplyFlag()) { return; }
    this->Concatenation->SetPreMultiplyFlag(1); this->Modified(); };

  // Description:
  // Sets the internal state of the transform to PostMultiply. All subsequent
  // operations will occur after those already represented in the
  // current transformation.  In homogeneous matrix notation, M = A*M where
  // M is the current transformation matrix and A is the applied matrix.
  // The default is PreMultiply.
  void PostMultiply()  { 
    if (!this->Concatenation->GetPreMultiplyFlag()) { return; }
    this->Concatenation->SetPreMultiplyFlag(0); this->Modified(); };

  // Description:
  // Get the total number of transformations that are linked into this
  // one via Concatenate() operations or via SetInput().
  int GetNumberOfConcatenatedTransforms() {
    return this->Concatenation->GetNumberOfTransforms() + 
      (this->Input == NULL ? 0 : 1); };

  // Description
  // Get one of the concatenated transformations as a vtkAbstractTransform.
  // These transformations are applied, in series, every time the 
  // transformation of a coordinate occurs.  This method is provided
  // to make it possible to decompose a transformation into its
  // constituents, for example to save a transformation to a file.
  vtkLinearTransform *GetConcatenatedTransform(int i)
    {
      vtkAbstractTransform *t;
      if (this->Input == NULL)
        {
        t=this->Concatenation->GetTransform(i);
        }
      else if (i < this->Concatenation->GetNumberOfPreTransforms())
        {
        t=this->Concatenation->GetTransform(i);
        }
      else if (i > this->Concatenation->GetNumberOfPreTransforms())
        {
        t=this->Concatenation->GetTransform(i-1);
        }
      else if (this->GetInverseFlag())
        {
        t=this->Input->GetInverse();
        }
      else
        {
        t=this->Input;
        }
      return static_cast<vtkLinearTransform *>(t);
    }

  // Description:
  // Get the x, y, z orientation angles from the transformation matrix as an
  // array of three floating point values.  
  void GetOrientation(double orient[3]);
  void GetOrientation(float orient[3]) {
    double temp[3]; this->GetOrientation(temp); 
    orient[0] = static_cast<float>(temp[0]); 
    orient[1] = static_cast<float>(temp[1]); 
    orient[2] = static_cast<float>(temp[2]); };
  double *GetOrientation() { 
    this->GetOrientation(this->ReturnValue); return this->ReturnValue; };

  // Description:
  // Convenience function to get the x, y, z orientation angles from 
  // a transformation matrix as an array of three floating point values.  
  static void GetOrientation(double orient[3], vtkMatrix4x4 *matrix);

  // Description:
  // Return the wxyz angle+axis representing the current orientation.
  // The angle is in degrees and the axis is a unit vector.
  void GetOrientationWXYZ(double wxyz[4]);
  void GetOrientationWXYZ(float wxyz[4]) {
    double temp[4]; this->GetOrientationWXYZ(temp); 
    wxyz[0]=static_cast<float>(temp[0]); 
    wxyz[1]=static_cast<float>(temp[1]); 
    wxyz[2]=static_cast<float>(temp[2]); 
    wxyz[3]=static_cast<float>(temp[3]);};
  double *GetOrientationWXYZ() { 
    this->GetOrientationWXYZ(this->ReturnValue); return this->ReturnValue; };

  // Description:
  // Return the position from the current transformation matrix as an array
  // of three floating point numbers. This is simply returning the translation 
  // component of the 4x4 matrix.
  void GetPosition(double pos[3]);
  void GetPosition(float pos[3]) {
    double temp[3]; this->GetPosition(temp); 
    pos[0] = static_cast<float>(temp[0]); 
    pos[1] = static_cast<float>(temp[1]); 
    pos[2] = static_cast<float>(temp[2]); };
  double *GetPosition() { 
    this->GetPosition(this->ReturnValue); return this->ReturnValue; };

  // Description:
  // Return the scale factors of the current transformation matrix as 
  // an array of three float numbers.  These scale factors are not necessarily
  // about the x, y, and z axes unless unless the scale transformation was
  // applied before any rotations.  
  void GetScale(double scale[3]);
  void GetScale(float scale[3]) {
    double temp[3]; this->GetScale(temp); 
    scale[0] = static_cast<float>(temp[0]); 
    scale[1] = static_cast<float>(temp[1]); 
    scale[2] = static_cast<float>(temp[2]); };
  double *GetScale() { 
    this->GetScale(this->ReturnValue); return this->ReturnValue; };

  // Description:
  // Return a matrix which is the inverse of the current transformation
  // matrix.
  void GetInverse(vtkMatrix4x4 *inverse);

  // Description:
  // Return a matrix which is the transpose of the current transformation
  // matrix.  This is equivalent to the inverse if and only if the 
  // transformation is a pure rotation with no translation or scale.
  void GetTranspose(vtkMatrix4x4 *transpose);

  // Description:
  // Set the input for this transformation.  This will be used as the
  // base transformation if it is set.  This method allows you to build
  // a transform pipeline: if the input is modified, then this transformation
  // will automatically update accordingly.  Note that the InverseFlag,
  // controlled via Inverse(), determines whether this transformation
  // will use the Input or the inverse of the Input.
  void SetInput(vtkLinearTransform *input);
  vtkLinearTransform *GetInput() { return this->Input; };

  // Description:
  // Get the inverse flag of the transformation.  This controls
  // whether it is the Input or the inverse of the Input that
  // is used as the base transformation.  The InverseFlag is
  // flipped every time Inverse() is called.  The InverseFlag
  // is off when a transform is first created.
  int GetInverseFlag() {
    return this->Concatenation->GetInverseFlag(); };

  // Description:
  // Pushes the current transformation onto the transformation stack.
  void Push() { if (this->Stack == NULL) { 
                    this->Stack = vtkTransformConcatenationStack::New(); }
                this->Stack->Push(&this->Concatenation); 
                this->Modified(); };

  // Description:
  // Deletes the transformation on the top of the stack and sets the top 
  // to the next transformation on the stack.
  void Pop() { if (this->Stack == NULL) { return; }
               this->Stack->Pop(&this->Concatenation);
               this->Modified(); };

  // Description:
  // Check for self-reference.  Will return true if concatenating
  // with the specified transform, setting it to be our inverse,
  // or setting it to be our input will create a circular reference.
  // CircuitCheck is automatically called by SetInput(), SetInverse(),
  // and Concatenate(vtkXTransform *).  Avoid using this function,
  // it is experimental.
  int CircuitCheck(vtkAbstractTransform *transform);

  // Return an inverse transform which will always update itself
  // to match this transform.
  vtkAbstractTransform *GetInverse() { 
    return vtkLinearTransform::GetInverse(); }

  // Description:
  // Make a new transform of the same type.
  vtkAbstractTransform *MakeTransform();

  // Description:
  // Override GetMTime to account for input and concatenation.
  unsigned long GetMTime();

  // Description:
  // Use this method only if you wish to compute the transformation in
  // homogeneous (x,y,z,w) coordinates, otherwise use TransformPoint().
  // This method calls this->GetMatrix()->MultiplyPoint().
  void MultiplyPoint(const float in[4], float out[4]) {
    this->GetMatrix()->MultiplyPoint(in,out);};
  void MultiplyPoint(const double in[4], double out[4]) {      
    this->GetMatrix()->MultiplyPoint(in,out);};

protected:
  vtkTransform ();
  ~vtkTransform ();

  void InternalDeepCopy(vtkAbstractTransform *t);

  void InternalUpdate();

  vtkLinearTransform *Input;
  vtkTransformConcatenation *Concatenation;
  vtkTransformConcatenationStack *Stack;

  // this allows us to check whether people have been fooling
  // around with our matrix
  unsigned long MatrixUpdateMTime;

  float Point[4];
  double DoublePoint[4];
  double ReturnValue[4];
private:
  vtkTransform (const vtkTransform&);  // Not implemented
  void operator=(const vtkTransform&);  // Not implemented
};

#endif
